Speed Limits Revisted
This month Texas Highway 130 recently opened with a speed limit of 85 MPH, which is currently the highest in the U.S. This apparently flies in the face of conventional wisdom that higher speeds result in more deaths. The reality is that appropriate safe speed is not a constant and varies with many factors, which have changed over the years.
Historically, speed has been linked to safety. However, other factors such as car safety equipment, road design, and driver capability have a major impact as well. We'll take a look at each of these factors but first lets view a video on what the people in Texas think about their new highway.
I've long maintained the reason why speed is so often linked with collisions is that, by far, it is the easiest item to measure. When the police arrive at the scene of a crash, they have limited time to investigate and the easy to determine factors go to the top of the list. After all, how are the other factors determined, such as drowsy driving, distracted driving, and just plain not paying attention? In many cases it is impossible to determine the real factors of a crash, so if there was speed involved that's where the blame is placed.
After all, at one time states like Montana had "reasonable and prudent" speed limits and even today the German Autobahns have an unlimited speed limit. I have traveled in both of these situations without incident.
A look at safety factors shows several contributors, including:
- Cars safety equipment has increased dramatically over the years. Cars now include supplemental safety restraints (a.k.a. airbags) in many places throughout the cabin. Seat belts are much safer and have smart features, such as tightening during a crash. Steering wheels now collapse so they aren't the "crash weapon" of the past. Modern cars now contain crush zones that absorb energy thus reducing the effects of the impact on the driver and passengers.
- Road safety has also improved dramatically. The aforementioned road in Texas is a modern highway built with safety in mind. The same is true of the German Autobahns. Many highways have divided highways with little interaction between cars going in different directions. Exit and entry ramps are designed to not impede traffic flow. Rumble strips are placed along the edges of the road to alert drivers when they are meandering. Lanes are wider and road signage requires less concentration to read.
- Driver training is one of the areas that could still use improvement. Now that drivers education is taught by private schools and online drivers ed is available, the level of training has steadily been improving. Generally, the U.S. has very limited requirements for driver education and could use improvement. In most states, most adults can obtain a drivers license without any proper training, which is not allowed in most European countries. Even though it's better than in the past, we need to continue to raise the bar for driver education standards.
- Driver attitude is probably one of the biggest factors in driving safety. A wide range of factors, including drowsy driving, distracted driving, and left lane campers contribute greatly to reducing the safety on U.S. roads. Drivers often make mental mistakes that cause serious crashes simply by not paying attention to the task at hand, which is driving their vehicle.
There have been many studies done over the years on speed as it relates to safety, some show a correlation. However, others demonstrate increased speed limits do not have a detrimental impact on safe driving. A good example is the peer-reviewed research paper "Did the 65 MPH Speed Limit Save Lives", which showed that increasing the speed limit from 55 MPH to 65 MPH actually decreased fatalities.
The bottom line is the need to understand the factors of crashes. This understanding can lead to solutions that can reduce traffic fatalities. By simply stating that speed was involved, we are brushing under the carpet the true causes of car crashes.